Heavier-than-air flight vehicles have been known for that last 100 years or so, and include airplanes and helicopters. Such flight vehicles are used in many applications where speed is necessary to transport people and/or cargo to distant locations.
In many applications, it is desirable to transport people and/or materials to distant locations where the terrain is rugged and facilities may be lacking. For example, in many military applications troops and equipment must be delivered rapidly to intercept enemy troops. The use of flight vehicles is often the quickest method to transport such troops and equipment.
While airplanes have excellent lifting capacity and altitude capabilities, most airplanes lack vertical takeoff or landing (VTOL) or even short takeoff or landing (STOL) capabilities, and they typically require a large open space for takeoff and landing. In many rugged landing sites, traditional airplanes are not suitable.
Helicopters can land and take off vertically, and have exceptional maneuverability. Helicopters are sometimes subject to accidents and failures, such as engine or rotor failures, which in some situations will lead to a failure and loss of the helicopter. Helicopters also use rotors (as opposed to propellers), which involve swash plates and other complicated mechanisms. Additionally, many helicopters have difficulty operating at high altitudes. Helicopters also tend to have slower flight speeds than do traditional aircraft.
Vertical takeoff airplanes are known which have propeller assemblies which can be rotated from a horizontal position (i.e., with propeller blades spinning in a generally horizontal plane, e.g., to provide vertically-directed thrust/lift for vertical takeoff) to a more vertical position (i.e., with propeller blades spinning in a generally vertical plane, e.g., to provide horizontally-directed thrust for forward flight). Examples of such aircraft include the V-22 Osprey. A complication of many tilt-rotor designs is that the wing structure blocks a portion of the propeller or rotor thrust. For example, when the propeller spins in a horizontal plane, i.e., when taking off/landing vertically and/or very short take-off/landing, thrust/propwash from the propeller strikes the top of the wing portion adjacent the propeller. When in the forward flight mode, e.g., with the propellers spinning in a generally vertical plane, thrust/propwash from the propeller strikes the wing and passes/interacts with the wing. This interaction of propwash with the wing reduces the thrust provided for forward thrust and/or vertical/short lift-off/landing, and also can interfere with aircraft controls and stability.
What has been needed is a vehicle that can be easily delivered and deployed for flight, with heavy lift and excellent flight characteristics even at high altitudes, which can fly in horizontal flight at conventional airplane speeds yet take off vertically and/or in very short takeoff mode, that is adaptable to many uses. Due to issues with currently available vertical lift vehicles, a need exists for a vertical lift vehicle that has improved lift characteristics, reduced cost, and increased reliability. The current invention meets those needs.